This invention relates to detergent compositions utilizing a builder selected from the group comprising a copolymer of divinyl ether and maleic anhydride (DIVEMA), polymers of divinyl ether, maleic anhydride and vinyl acetate, and novel polymers of divinyl ether, maleic anhydride and at least one copolymerizable comonomer, selected from the group consisting of alkenyl alkyl ethers, alkyl acrylates, alkenyl carboxyalkyl ethers, vinyl esters of C.sub.1 or C.sub.3 or greater carboxylic acids, unsaturated carboxylic acids, unsaturated dicarboxylic acids and their esters, and olefins.
The DIVEMA copolymer is best known as an experimental antitumor and antiviral drug (Pyran). See Morahan, Page S., et al, Cancer Treat. Rep., 62 (11) 1797-805 (1978). The preparation and the composition of the saturated linear DIVEMA copolymer were disclosed in U.S. Pat. No. Re. 26,407 to Butler, issued Jun. 11, 1968. Use of the DIVEMA copolymer, in a preferred molecular weight range from about 1,000 to about 10,000, as an aqueous dispersant for fine solids such as pigments, clay and organic polymers was disclosed in U.S. Pat. No. 3,085,077 to Floyd, issued Apr. 9, 1963. Its use as a water loss prevention agent in gas and oil well drilling fluids was disclosed in U.S. Pat. No. 3,157,599 to Gloor, issued Nov. 17, 1964.
The terpolymer of divinyl ether, maleic anhydride and vinyl acetate was disclosed in U.S. Pat. No. 2,640,039 to Williams, issued May 26, 1953. Additionally, this patent discloses the use of this terpolymer to thicken and size aqueous solutions, form gels or films, form protective colloids, disperse agents in aqueous solutions and replace gums.
The remaining class of polymers which are useful as builders in detergent compositions disclosed herein are novel polymers of divinyl ether, maleic anhydride and at least one selected copolymerizable comonomer.
Detergent compositions are generally a blend of a surfactant(s), builder(s) and, optionally, ion exchangers, fillers, alkalies, anticorrosion materials, antiredeposition materials, bleaches, enzymes, optical brighteners, fragrances and other components selected for particular applications.
Builders are used to improve the effectiveness of detergent compositions and thereby improve their whitening powers. Polyphosphate compounds, such as sodium tripolyphosphate, have long been in use as builders, particularly because of their relatively low cost and their utility in increasing the whitening powers of detergent compositions. It is theorized, however, that the presence of these polyphosphates tends to contribute to the growth of algae in lakes and rivers to a degree sufficient to cause eutrophication of these waters. For many years there has been legislative pressure to lower or discontinue their usage completely in detergent compositions to control phosphate pollution. Thus, detergent manufacturers continue to search for effective, non-phosphate detergent builders.
The manner in which detergent builders improve the cleaning powers of detergent compositions is related to a combination of such factors as emulsification of soil particles, solubilization of water insoluble materials, promoting soil suspension in the wash water so as to retard soil redeposition, sequestering of metallic ions, and the like.
Alternatives for sodium tripolyphosphate are widely used by detergent formulators. Many materials are or have been used as builders in detergent formulations. All have one or more drawbacks that offset their value in the formulations. Compositions and materials change frequently as formulators attempt to improve performance of cleaning while offering greater convenience in handling as well as keeping materials cost as low as possible.
Among the materials that have been suggested for use as detergent builders are the ether carboxylates disclosed in U.S. Pat. No. 4,663,071 to Bush, et al., issued May 5, 1987; the copolymers of maleic anhydride and sulfonated styrene or 2-acrylamido-2-methyl propane sulfonic acid disclosed in U.S. Pat. No. 4,711,740 to Carter, et al., issued Dec. 8, 1987; and the carboxylated bicyclic compounds and salts thereof disclosed in U.S. Pat. No. 3,898,034 to Szymanski, et al., issued Aug. 5, 1975.
Notwithstanding the existence of the foregoing types of detergent builders, there remains a continuing need to identify additional nonphosphorus sequestering agents, such as polymers prepared from divinyl ether and maleic anhydride, which can be prepared commercially and utilized as builders in commercial detergent compositions. Accordingly, it is an object of this invention to provide detergent compositions employing effective, non-phosphate builders as a replacement, in whole, or in part, for phosphate builders.
It is a further object of this invention to provide novel polymers of divinyl ether, maleic anhydride and at least one selected copolymerizable comonomer, which are useful as detergent builders.